Multiple short bouts of exercise are better than a single continuous bout for cardiometabolic health: a randomised crossover trial.

PURPOSE: To compare cardiometabolic responses to five consecutive days of daily postprandial exercise accumulated in three 10-min bouts or a single 30-min bout to a no-exercise control. METHODS: Ten insufficiently active adults completed three trials in a randomised order. Each trial comprised five consecutive days of 30 min of exercise either accumulated in three separate 10-min bouts (ACC) after main meals; a single 30-min bout after dinner (CONT); or a no-exercise control (NOEX). Glucose regulation was assessed from an oral glucose tolerance test. Applanation tonometry was used to assess pulse wave velocity approximately 12 h following completion of the final trial. RESULTS: Area under the 2-h glucose curve was similar for CONT (mean; 95% CI 917 mmol L-1 2 h-1; 815 to 1019) and ACC (931 mmol L-1 2 h-1; 794 to 1068, p = 0.671). Area under the 2-h insulin curve was greater following NOEX (70,328 pmol L-1 2 h-1; 30,962 to 109,693) than ACC (51,313 pmol L-1 2 h-1: 21,822 to 80,806, p = 0.007). Pulse wave velocity was lower for ACC (5.96 m s-1: 5.38 to 6.53) compared to CONT (6.93 m s-1: 5.92 to 7.94, p = 0.031) but not significantly lower for ACC compared to NOEX (6.52 m s-1: 5.70 to 7.34, p = 0.151). CONCLUSION: Accumulating 30 min of moderate-intensity walking in three bouts throughout the day is more effective at reducing markers of cardiometabolic health risk in insufficiently active, apparently healthy adults than a single daily bout. Both accumulated and single-bout walking were equally as effective at reducing postprandial glucose concentrations compared to a no-exercise control. Therefore, accumulating exercise in short bouts after each main meal might be more advantageous for overall cardiometabolic health.

A comparison of acute glycaemic responses to accumulated or single bout walking exercise in apparently healthy, insufficiently active adults.

OBJECTIVES: To investigate the acute glyacaemic response to accumulated or single bout walking exercise in apparently healthy adults. DESIGN: Three arm, randomised crossover control study. METHODS: Ten adults (age: 50±12.6 y; BMI 29.0±5.4kgm-2) completed three separate trials comprising three 10-min walking bouts after breakfast, lunch, and dinner (APPW), a single 30-min walking bout after dinner only (CPPW), or a no-exercise control (NOEX). Participants walked on a treadmill at a moderate intensity of 55%-70% heart rate reserve. Two-hour postprandial glucose response was assessed using a continuous glucose monitor. RESULTS: There was a difference in the pattern of the glucose response between the trials during the two hours following dinner (p<0.001). Postprandial dinner glucose concentrations were not different between APPW and CPPW but were up to 1.01mmolL-1 lower than NOEX (partial eta2=0.21, p=0.041). CONCLUSIONS: Ten minutes of moderate intensity walking completed 30min after each meal lowers postprandial dinner glucose concentrations in comparison to no-exercise, and reduces glucose by a similar magnitude as a single 30-min bout after the evening meal. Short bouts of exercise after each meal may be recommended to minimise glucose elevations after dinner that might increase risk of cardiometabolic disease.